Logit模型在南广高铁线客流分担预测中的应用

对分担率进行科学的预测是交通运输规划的基础性工作,是制定运输决策的重要依据。文章经过比较选取多项Logit模型为分担率预测模型,介绍了模型建立与求解的方法,并运用该模型对南广高铁沿线客流分担率进行预测分析。     

考虑相变过程岩体孔隙率对寒区隧道温度场时空规律影响研究

为研究寒区隧道围岩在持续低温作用或冻融循环作用过程中,考虑岩体相变过程中多相体各组分变化引起的岩石热学参数差异对围岩温度场时空变化规律的影响,利用已有岩体未冻水含量研究成果,进一步推导不同孔隙率下岩体的热学参数计算公式。基于多孔介质模型建立考虑相变过程的围岩温度场计算模型,分析考虑潜热时不同孔隙率下围岩冻结缘的空间形态变化规律,及相变过程对温度场的影响。研究结果表明： 1）饱和岩体孔隙率越高,对岩体整体热学参数影响越大; 2）低温持续作用围岩时,冻结缘向围岩深处移动并不断变宽,其宽度与其深度呈线性关系; 3）饱和围岩孔隙率对冻结缘移动速度影响较大,但对其宽度基本无影响; 4）由于相变潜热,岩体在冻融循环过程中围岩温度时程曲线出现不对称阶梯状形态,且其阶梯形状宽度与围岩孔隙率呈正相关; 5）冻融循环过程中,升温及降温过程中冻结缘临近岩体温度梯度存在差异引起的传热效率不同直接导致升温、降温时程曲线的不对称性特征出现; 6）沿硐室围岩径向向外,各处围岩体的温度时程函数与加载的温度函数存在着振幅衰减和相位滞后的现象,且岩体孔隙率越高该现象越明显。     

基于远、近期合建的折多山公路隧道总体设计方案研究

为解决特长公路隧道升级改造困难问题,以折多山公路隧道项目为依托,创新性地提出远、近期合建的总体设计方案。通过交通量预测、工程造价、运营通风及逃生救援等方面综合比较,得出可实施的合建方案： 先期建设二级公路隧道主洞,设2段非贯通平导,后期直接将二级公路隧道作为高速公路隧道右洞,并贯通二级公路隧道平导作为高速公路隧道左洞。合建方案能有效节约工程造价,降低社会耗能。     

Effects of the ‘Belt and Road’ initiative on the wine import logistics of China

China’s Belt and Road (BR) initiative is expected to facilitate international trade between the countries involved. In this study, we review the special requirements of wine logistics and the market growth potential of wine consumption in China. A model minimizing generalized logistical costs is developed and applied to wine imports in China, so that the best candidate cities in which to locate transport gateways and distribution centers can be identified. Our analysis suggests that the most preferred gateways are Shanghai, Tianjin, Guangzhou, and Hong Kong, which all have similar delivery costs. In comparison, Beijing and Chongqing have much higher delivery costs, mainly because they do not have good access to marine transport and/or efficient domestic distribution networks. For long-distance intercontinental transport of large volumes of wine, marine shipping remains the only viable delivery mode. However, wine distribution within China extensively uses air, road, and water transport. Therefore, cities with excellent multi-modal transport services are better positioned to become wine logistics gateways. Our study also highlights the importance of value-added services and good government support, which are important factors that influence distribution costs and quality.     

Locating rental stations and bikeways in a public bike system

To determine the spatial distribution of rental stations and bikeways in a public bike system, this paper proposes a facility location and network design model. The model is developed as a multi-objective programing problem that considers four objectives (minimizing cyclist risk, maximizing cyclist comfort, minimizing adverse impacts on traffic and maximizing service coverage) and multiple constraints (monetary budget, network connectivity, station spacing, bikeway types, station number and value ranges of decision variables). The ε-constraint method solves the programing problem for the public bike system in Daan District, Taipei City, Taiwan. The nine non-dominated alternatives generated are all markedly better than existing locations of rental stations and bikeways. Scenario analysis results indicate that increasing the construction budget for bikeways significantly improves cyclist safety and comfort whilst increasing the adverse impact on traffic. Planners can use this model to develop public bike systems that spatially integrate rental stations and bikeway networks.     

Incomplete cost – incomplete benefit analysis in transport appraisal

This paper examines the current application of transport appraisal in the UK, in particular exploring the partiality of cost–benefit analysis (CBA) within the wider multi-criteria analysis (MCA) process. It argues that applying a quantitative assessment of the varied impacts of complex transport projects can only be partial within the CBA. Analysis can overlook social, human life, environmental and built environment impacts, and projects can be inconsistent with the planning strategy for an area. The application of CBA is critically reviewed using two case studies: the proposed upgrade of the South Fylde railway line and the Heysham-M6 Link Road, both from North West England. A participatory MCA process is suggested to help improve the process of transport appraisal, as part of an improved public debate on transport investment priorities.     

Initial public offerings in the port industry: exploring the determinants of underpricing

The capital-intensive nature of the port industry and the long payback period of port investments traditionally determine high financial needs for operating the business. Due to the growing financial requirements for developing greenfield mega-projects and feeding international terminal operators’ overseas expansion, equity markets are expected to extend their role in promoting the industry. In this perspective, the underpricing phenomenon, which represents a direct cost for the issuer during initial public offering (IPO) and discourages companies from going public, is neglected by port literature. The paper explores the antecedents of IPO underpricing in ports. Building upon extant finance and port literature, firm characteristics, transaction features, and country-specific variables are tested as determinants of IPOs’ initial returns. For the aim of this study, 58 port-related IPOs taking place on international stock exchanges are examined, and ordinary least squares regression analysis is performed. The study offers unprecedented understandings of the phenomenon and supports port managers in facing financial challenges. Before launching the IPO, financial executives are invited to carefully identify time-window opportunities, and to monitor underwriters’ reputation when selecting financial partners. Findings bring insights for policymakers, as the public listing of port companies emerges a viable option for implementing port reform.     

Simulating ad-hoc demand-responsive transportation: a comparison of three approaches

Transport models are used to evaluate new infrastructure and public transport services, varied levels of demand, and new ideas for demand management. Exploring these proposals virtually is easier than implementation and testing in situ. However, existing models are based around traditional forms of transportation. As part of a feature analysis using a case study approach, three different simulation packages (a simple custom-developed package, traffic microsimulation, and agent-based simulation) are used to develop and demonstrate simulations of demand-responsive transportation (DRT) and analyze the advantages and disadvantages of each simulation approach for evaluating DRT. While the simulations display some relational replication (meaning they produce similar relational patterns with respect to certain variables), they do not show distributional replication (that is, the value of the results is not statistically similar), meaning that under- or over-estimation of predicted travel could occur. Recommendations for the application of each modeling approach are made.     

Intermodal transport in freight distribution: a literature review

There has been significant growth in research on intermodal transport in freight distribution since the 1990s. Differentiating itself from previously published literature reviews, this paper evaluates the current state of this research using Systematic Literature Review methodology. The complementary aims are: (a) to identify the research lines developed and to propose a criterion for classifying the literature, and (b) to discuss the empirical evidence that identifies existing interrelationships. The analysis has enabled three main lines of research to be identified. The first research line, basic principles of intermodal transport, groups together works related to the definition of intermodal transport and the results obtained using this transportation system. The second, improvements to the way that intermodal transport systems work, frames elements and variables that impact intermodal transport systems’ logistics efficiency, such as quality of service, information and communication systems, and freight planning and linkages among system operators to provide an adequate service. Finally, the third line, intermodal transport system modelling, identifies the main variables used to optimise these transport systems, the different focuses and approaches used in modelling, and the advantages and disadvantages of each focus. These research lines take in more specific sublines that incorporate articles that develop related research questions. Lastly, the discussion of the content of each of these research sublines enables us to identify gaps in the literature and comment on directions for future research.     

Factors influencing travel mode choice among families with young children (aged 0–4): a review of the literature

Life events, such as the birth of a child, disrupt habitual travel behaviour and provide a valuable opportunity to influence the adoption of sustainable transport practices. However, in order for sustainable travel practices to be adopted, an understanding is required of the factors that influence travel mode choice among families with young children. Research in this field is particularly timely given many in the millennial generation, a comparably large cohort, are approaching this life stage. This comprehensive literature review develops a framework of factors influencing travel mode choice among families with young children. The findings reveal a multitude of factors influence decisions about mode choice, and, in particular, encourage travel by car, when travelling with young children. The paper concludes with an agenda for future research about travel among families with young children, a largely overlooked group of transport users.